OPINION:
The MMP electoral system adopted in 1993 seeks to balance two competing objectives – proportionality and stability. The mechanism by which it attempts to do this is the party vote threshold.

Parties which win enough votes to pass the threshold – currently 5 per cent – are entitled to a proportionate share of seats in Parliament. Parties which do not pass the threshold are denied list seats even though on a strictly proportional basis they might be entitled to up to five. The barrier is intended to prevent a proliferation of tiny parties making effective government impossible. Evidence since the switch to MMP suggests it has worked. The major political parties have been forced to take note of the views of their parliamentary allies, but have not been prevented from governing.

There is one exception to the party vote threshold. Parties which win an electorate seat do not have to pass the threshold to secure list seats. Hence, at different times, NZ First, ACT, UnitedFuture and the Progressives have all gained list seats without getting 5 per cent of the vote.

It is that exception which shapes as the main bone of contention as the Government considers its response to the Electoral Commission's just-completed review of the system.

The commission has recommended the electorate seat waiver, imported from the German system, be abolished.

In Germany the waiver ensures that a party with strong regional, but not national, support is not denied an effective voice in the federal parliament. In New Zealand's smaller, more homogenous political landscape there is no need for such a protection.

As members of the royal commission which recommended the adoption of MMP have said, its inclusion here was a mistake.

It gives voters in some electorates more influence over the makeup of Parliament than voters in other electorates, it encourages political gameplaying of the sort that saw John Key have a much-publicised cup of tea with ACT leader John Banks during the last campaign and it can lead to unfairness. In 2008, NZ First won 4.1 per cent of the party vote but gained no seats. The same year ACT won 3.6 per cent of the vote but received 5 seats because its then-leader Rodney Hide won the Epsom electorate.

Two of National's allies – ACT and Peter Dunne's UnitedFuture – are arguing for the retention of the waiver. It is not difficult to see why. ACT has not passed the 5 per cent mark since 2002 and UnitedFuture has only managed to do so once in six attempts.

However, the shape of the electoral system should not be determined by politicians' interests, but by what is in the interests of the public. That is a fair system that facilitates public trust.

A better safeguard for smaller parties is the other of the commission's major recommendations – that the party vote threshold be reduced from 5 per cent to 4 per cent. It is not an insurmountable hurdle. Rather than trying to tilt the system in their favour, ACT and UnitedFuture should try to convince more people to vote for them.